Introduction General part

2.2 Selection of the half-finished product type.
One of the most pressing issues in mechanical engineering is the production of sheet metal. Therefore, an attempt is made to use the ehg optimal extraction method to obtain them. The blanks are divided into clean and rough blanks. Clean blanks are blanks that are not cut after preparation, and whose dimensions and cleanliness correspond to the dimensions and cleanliness indicated in the finished drawing. Sketches are workpieces that require mechanical machining to cut a piece to create a detail of size, accuracy, and cleanliness that meets the requirements of the drawing.
Workpieces for machine parts are mainly prepared in the following ways:
1) by casting of ferrous and non-ferrous metals;
2) by working with pressure (hammering and stamping);
3) rolled ferrous and non-ferrous metals;
4) metal-ceramics (by powder metallurgy);
5) welding - by joining parts together as a whole;
6) non-metallic materials (plastics, etc.).
Factors such as the choice of method of preparation, the size and material of the part, the task of the worker, the technical requirements for its preparation, the annual program and the general structure determine. To solve this problem, it is necessary to ensure that the size and structure of the workpiece is as close as possible to the size and structure of the part. But it should be borne in mind that increasing the accuracy of the workpiece and complicating its structure will lead to an increase in its cost. Therefore, the optimal method of obtaining billets is the method when the cost of billets is low. When there are pieces, we analyze the existing methods of obtaining billets and use the casting method, which is the optimal method of preparation of billets for our detail under the given production conditions.
S_hfp =( )–(Q-q) soums
Here: S1 - cost of one ton of material, soums
S_a = 510000 –– Price of 1 ton of waste, soums
R_t = 1.0 ([2], 37b) - accuracy coefficient;
R_c = 0.84 ([2], 2.12j, 38b) - coefficient of complexity;
R_b = 1.1 ([2], 2.12j, 38b) - coefficient of weight;
R_m = 0.84 ([2], 33b) - material coefficients;
R_n = 1.0 ([2], 34b) - serialization coefficient;
soums.
Determine the coefficient of metal use:
;
Here: Q is detail weight in kg; Q_hfp is the weight of the blank.